Murguialday RA, Jeremy Jeremy Hill, Bensch M, Martens SMM, Halder S, Nijboer F, Birbaumer N, et al.. Transition from the locked in to the completely locked-in state: a physiological analysis. Clin Neurophysiol [Internet]. 2011;122(5):925-33. http://www.ncbi.nlm.nih.gov/pubmed/20888292